<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onMounted, onUnmounted, PropType, ref } from 'vue'
const props = defineProps({
  bannerList: {
    type: Array as PropType<BannerItem[]>,
    required: true,
  },
  autoPlay: {
    type: Boolean,
    default: false,
  },
  duration: {
    type: Number,
    default: '2000',
  },
})

//  判断轮播图是否会自动播放
let Timer = -1
const play = () => {
  if (!props.autoPlay) return
  // 防止开启多个定时器
  clearInterval(Timer)
  Timer = window.setInterval(() => {
    // 判断轮播图的小圆点是否到头了
    if (active.value === props.bannerList.length - 1) {
      active.value = -1
    }
    active.value++
  }, props.duration)
}
// 销毁定时器
const stop = () => {
  clearInterval(Timer)
}
// 在钩子函数中来调用定时器
onMounted(() => {
  play()
})
onUnmounted(() => {
  stop()
})
// 注册箭头点击事件
const prev = () => {
  stop()
  if (active.value === 0) {
    active.value = props.bannerList.length - 1
  } else {
    active.value--
  }
  play()
}
const next = () => {
  stop()
  if (active.value === props.bannerList.length - 1) {
    active.value = 0
  } else {
    active.value++
  }
  play()
}
// 控制小圆点的高亮
const active = ref(0)
</script>

<template>
  <div class="xtx-carousel">
    <!-- 轮播图 -->
    <ul class="carousel-body" @mouseenter="stop()" @mouseleave="play()">
      <!-- fade的显示与隐藏 轮播图与小圆点的关联 -->
      <li
        class="carousel-item"
        :class="{ fade: active === index }"
        v-for="(item, index) in props.bannerList"
        :key="item.id"
        duration
        autoPlay
      >
        <RouterLink :to="item.hrefUrl">
          <img :src="item.imgUrl" alt="" />
        </RouterLink>
      </li>
    </ul>
    <!-- 左箭头 -->
    <a href="javascript:;" class="carousel-btn prev" @click="prev"
      ><i class="iconfont icon-angle-left"></i
    ></a>
    <!-- 右箭头 -->
    <a href="javascript:;" class="carousel-btn next" @click="next"
      ><i class="iconfont icon-angle-right"></i
    ></a>
    <!-- 小圆点 -->
    <div class="carousel-indicator">
      <span
        :class="{ active: active === index }"
        v-for="(item, index) in props.bannerList"
        :key="item.id"
      ></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>
